Factors Associated With Noncompletion of Latent Tuberculosis Infection Treatment: Experience From the PREVENT TB Trial in the United States and Canada.

BACKGROUND: Overall rates of noncompletion of treatment (NCT) for latent tuberculosis infection (LTBI) in the PREVENT TB trial were 18% for 3 months of directly observed once-weekly rifapentine (maximum dose, 900 mg) plus isoniazid (maximum dose, 900 mg) (3HP-DOT) and 31% for 9 months of daily self-administered isoniazid (maximum dose, 300 mg; 9H-SAT). NCT for LTBI reduces its effectiveness. The study objective was to assess factors associated with NCT for LTBI among adult participants enrolled at US and Canadian sites of the PREVENT TB trial. METHODS: This was a post hoc exploratory analysis of the randomized, open-label PREVENT TB trial. Factors were analyzed by univariate and multivariate logistic regression (with enrollment site as a random effect). RESULTS: From 6232 participants analyzed, 1406 (22.6%) did not complete LTBI treatment (317 NCT attributed to an adverse event [NCT-AE] and 1089 NCT attributed to reasons other than an adverse event [NCT-O]). The proportion of NCT-AE was similar with both regimens (3HP-DOT = 6.4% vs 9H-SAT = 5.9%; P = .23); NCT-O was higher among participants enrolled in 9H-SAT (9H-SAT = 24.5% vs 3HP-DOT = 12.7%; P = .02). Among those in the NCT-AE group, being non-Hispanic and receiving 3HP-DOT, having cirrhosis and receiving 9H-SAT, alcohol consumption among men, and use of concomitant medication were associated with NCT-AE. Among those in the NCT-O group, receiving 9H-SAT, missing ≥1 early visit, men receiving 9H-SAT, men with a history of incarceration, alcohol abuse, use ever of intravenous drugs, younger age receiving 9H-SAT, and smoking were associated with NCT-O. CONCLUSIONS: Factors associated with NCT, such as missing a clinic visit early during treatment, might help identify persons for whom tailored interventions could improve completion of LTBI treatment. CLINICAL TRIALS REGISTRATION: NCT00023452.

Three months of rifapentine and isoniazid for latent tuberculosis infection.

BACKGROUND: Treatment of latent Mycobacterium tuberculosis infection is an essential component of tuberculosis control and elimination. The current standard regimen of isoniazid for 9 months is efficacious but is limited by toxicity and low rates of treatment completion. METHODS: We conducted an open-label, randomized noninferiority trial comparing 3 months of directly observed once-weekly therapy with rifapentine (900 mg) plus isoniazid (900 mg) (combination-therapy group) with 9 months of self-administered daily isoniazid (300 mg) (isoniazid-only group) in subjects at high risk for tuberculosis. Subjects were enrolled from the United States, Canada, Brazil, and Spain and followed for 33 months. The primary end point was confirmed tuberculosis, and the noninferiority margin was 0.75%. RESULTS: In the modified intention-to-treat analysis, tuberculosis developed in 7 of 3986 subjects in the combination-therapy group (cumulative rate, 0.19%) and in 15 of 3745 subjects in the isoniazid-only group (cumulative rate, 0.43%), for a difference of 0.24 percentage points. Rates of treatment completion were 82.1% in the combination-therapy group and 69.0% in the isoniazid-only group (P<0.001). Rates of permanent drug discontinuation owing to an adverse event were 4.9% in the combination-therapy group and 3.7% in the isoniazid-only group (P=0.009). Rates of investigator-assessed drug-related hepatotoxicity were 0.4% and 2.7%, respectively (P<0.001). CONCLUSIONS: The use of rifapentine plus isoniazid for 3 months was as effective as 9 months of isoniazid alone in preventing tuberculosis and had a higher treatment-completion rate. Long-term safety monitoring will be important. (Funded by the Centers for Disease Control and Prevention; PREVENT TB ClinicalTrials.gov number, NCT00023452.).

Completion, safety, and efficacy of tuberculosis preventive treatment regimens containing rifampicin or rifapentine: an individual patient data network meta-analysis.

BACKGROUND: 3 months of weekly rifapentine plus isoniazid (3HP) and 4 months of daily rifampicin (4R) are recommended for tuberculosis preventive treatment. As these regimens have not been compared directly, we used individual patient data and network meta-analysis methods to compare completion, safety, and efficacy between 3HP and 4R. METHODS: We conducted a network meta-analysis of individual patient data by searching PubMed for randomised controlled trials (RCTs) published between Jan 1, 2000, and Mar 1, 2019. Eligible studies compared 3HP or 4R to 6 months or 9 months of isoniazid and reported treatment completion, adverse events, or incidence of tuberculosis disease. Deidentified individual patient data from eligible studies were provided by study investigators and outcomes were harmonised. Methods for network meta-analysis were used to generate indirect adjusted risk ratios (aRRs) and risk differences (aRDs) with their 95% CIs. FINDINGS: We included 17 572 participants from 14 countries in six trials. In the network meta-analysis, treatment completion was higher for people on 3HP than for those on 4R (aRR 1·06 [95% CI 1·02-1·10]; aRD 0·05 [95% CI 0·02-0·07]). For treatment-related adverse events leading to drug discontinuation, risks were higher for 3HP than for 4R for adverse events of any severity (aRR 2·86 [2·12-4·21]; aRD 0·03 [0·02-0·05]) and for grade 3-4 adverse events (aRR 3·46 [2·09-6·17]; aRD 0·02 [0·01-0·03]). Similar increased risks with 3HP were observed with other definitions of adverse events and were consistent across age groups. No difference in the incidence of tuberculosis disease between 3HP and 4R was found. INTERPRETATION: In the absence of RCTs, our individual patient data network meta-analysis indicates that 3HP provided an increase in treatment completion over 4R, but was associated with a higher risk of adverse events. Although findings should be confirmed, the trade-off between completion and safety must be considered when selecting a regimen for tuberculosis preventive treatment. FUNDING: None. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.

CDC/NIH Workshop. Tuberculosis biomarker and surrogate endpoint research roadmap.

The Centers for Disease Control and Prevention and National Institutes of Health convened a multidisciplinary meeting to discuss surrogate markers of treatment response in tuberculosis. The goals were to assess recent surrogate marker research and to provide specific recommendations for (1) the qualification and validation of biomarkers of treatment outcome; (2) the standardization of specimen and data collection for future clinical trials, including a minimum set of samples and collection time points; and (3) the creation ofa specimen repository to support biomarker testing. This article summarizes these recommendations and provides a roadmap for their implementation.

Three months of weekly rifapentine and isoniazid for treatment of Mycobacterium tuberculosis infection in HIV-coinfected persons.

OBJECTIVE: Compare the effectiveness, tolerability, and safety of 3 months of weekly rifapentine and isoniazid under direct observation (3HP) versus 9 months of daily isoniazid (9H) in HIV-infected persons. DESIGN: Prospective, randomized, and open-label noninferiority trial. SETTING: The United States , Brazil, Spain, Peru, Canada, and Hong Kong. PARTICIPANTS: HIV-infected persons who were tuberculin skin test positive or close contacts of tuberculosis cases. INTERVENTION: 3HP versus 9H. MAIN OUTCOME MEASURES: The effectiveness endpoint was tuberculosis; the noninferiority margin was 0.75%. The tolerability endpoint was treatment completion; the safety endpoint was drug discontinuation because of adverse drug reaction. RESULTS: Median baseline CD4 cell counts were 495 (IQR 389-675) and 538 (IQR 418-729) cells/µl in the 3HP and 9H arms, respectively (P = 0.09). In the modified intention-to-treat analysis, there were two tuberculosis cases among 206 persons [517 person-years (p-y) of follow-up] in the 3HP arm (0.39 per 100 p-y) and six tuberculosis cases among 193 persons (481 p-y of follow-up) in the 9H arm (1.25 per 100 p-y). Cumulative tuberculosis rates were 1.01 versus 3.50% in the 3HP and 9H arms, respectively (rate difference: -2.49%; upper bound of the 95% confidence interval of the difference: 0.60%). Treatment completion was higher with 3HP (89%) than 9H (64%) (P < 0.001), and drug discontinuation because of an adverse drug reaction was similar (3 vs. 4%; P = 0.79) in 3HP and 9H, respectively. CONCLUSION: Among HIV-infected persons with median CD4 cell count of approximately 500 cells/µl, 3HP was as effective and safe for treatment of latent Mycobacterium tuberculosis infection as 9H, and better tolerated.

Treatment for preventing tuberculosis in children and adolescents: a randomized clinical trial of a 3-month, 12-dose regimen of a combination of rifapentine and isoniazid.

IMPORTANCE: Three months of a once-weekly combination of rifapentine and isoniazid for treatment of latent tuberculosis infection is safe and effective for persons 12 years or older. Published data for children are limited. OBJECTIVES: To compare treatment safety and assess noninferiority treatment effectiveness of combination therapy with rifapentine and isoniazid vs 9 months of isoniazid treatment for latent tuberculosis infection in children. DESIGN, SETTING, AND PARTICIPANTS: A pediatric cohort nested within a randomized, open-label clinical trial conducted from June 11, 2001, through December 17, 2010, with follow-up through September 5, 2013, in 29 study sites in the United States, Canada, Brazil, Hong Kong (China), and Spain. Participants were children (aged 2-17 years) who were eligible for treatment of latent tuberculosis infection. INTERVENTIONS: Twelve once-weekly doses of the combination drugs, given with supervision by a health care professional, for 3 months vs 270 daily doses of isoniazid, without supervision by a health care professional, for 9 months. MAIN OUTCOMES AND MEASURES: We compared rates of treatment discontinuation because of adverse events (AEs), toxicity grades 1 to 4, and deaths from any cause. The equivalence margin for the comparison of AE-related discontinuation rates was 5%. Tuberculosis disease diagnosed within 33 months of enrollment was the main end point for testing effectiveness. The noninferiority margin was 0.75%. RESULTS: Of 1058 children enrolled, 905 were eligible for evaluation of effectiveness. Of 471 in the combination-therapy group, 415 (88.1%) completed treatment vs 351 of 434 (80.9%) in the isoniazid-only group (P = .003). The 95% CI for the difference in rates of discontinuation attributed to an AE was -2.6 to 0.1, which was within the equivalence range. In the safety population, 3 of 539 participants (0.6%) who took the combination drugs had a grade 3 AE vs 1 of 493 (0.2%) who received isoniazid only. Neither arm had any hepatotoxicity, grade 4 AEs, or treatment-attributed death. None of the 471 in the combination-therapy group developed tuberculosis vs 3 of 434 (cumulative rate, 0.74%) in the isoniazid-only group, for a difference of -0.74% and an upper bound of the 95% CI of the difference of +0.32%, which met the noninferiority criterion. CONCLUSIONS AND RELEVANCE: Treatment with the combination of rifapentine and isoniazid was as effective as isoniazid-only treatment for the prevention of tuberculosis in children aged 2 to 17 years. The combination-therapy group had a higher treatment completion rate than did the isoniazid-only group and was safe. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00023452.

Rifapentine Pharmacokinetics and Tolerability in Children and Adults Treated Once Weekly With Rifapentine and Isoniazid for Latent Tuberculosis Infection.

BACKGROUND: In a phase 3, randomized clinical trial (PREVENT TB) of 8053 people with latent tuberculosis infection, 12 once-weekly doses of rifapentine and isoniazid had good efficacy and tolerability. Children received higher rifapentine milligram per kilogram doses than adults. In the present pharmacokinetic study (a component of the PREVENT TB trial), rifapentine exposure was compared between children and adults. METHODS: Rifapentine doses in children ranged from 300 to 900 mg, and adults received 900 mg. Children who could not swallow tablets received crushed tablets. Sparse pharmacokinetic sampling was performed with 1 rifapentine concentration at 24 hours after drug administration (C24). Rifapentine area under concentration-time curve (AUC) was estimated from a nonlinear, mixed effects regression model (NLME). RESULTS: There were 80 children (age: median, 4.5 years; range, 2-11 years) and 77 adults (age: median, 40 years; all ≥18 years) in the study. The geometric mean rifapentine milligram per kilogram dose was greater in children than in adults (children, 23 mg/kg; adults, 11 mg/kg). Rifapentine geometric mean AUC and C24 were 1.3-fold greater in children (all children combined) than in adults. Children who swallowed whole tablets had 1.3-fold higher geometric mean AUC than children who received crushed tablets, and children who swallowed whole tablets had a 1.6-fold higher geometric mean AUC than adults. The higher rifapentine doses in children were well tolerated. To obtain rifapentine exposures comparable in children to adults, dosing algorithms modeled by NLME were developed. CONCLUSIONS: A 2-fold greater rifapentine dose for all children resulted in a 1.3-fold higher AUC compared to adults administered a standard dose. Use of higher weight-adjusted rifapentine doses for young children are warranted to achieve systemic exposures that are associated with successful treatment of latent tuberculosis infection in adults.

The association between symptoms and microbiologically defined response to tuberculosis treatment.

RATIONALE: The lack of consistent associations between clinical outcomes and microbiological responses to therapy for some infectious diseases has raised questions about the adequacy of microbiological endpoints for tuberculosis treatment trials. OBJECTIVES: To evaluate the association between symptoms and microbiological response to tuberculosis treatment. METHODS: We performed a retrospective analysis of four clinical trials in which participants had culture-positive tuberculosis, standardized symptom assessment, and follow-up mycobacterial cultures. Two trials (studies 22 and 23) followed participants to identify recurrent tuberculosis; participants in studies 27 and 28 were only followed to treatment completion. MEASUREMENTS AND MAIN RESULTS: This analysis included 1,978 participants; 39 (2.0%) had culture-confirmed treatment failure, and 75 (3.9%) had culture-confirmed recurrence. Productive cough was associated with indices of increased mycobacterial burden at diagnosis (acid-fast smear grade, severity of radiographic abnormalities). Fever and sweats improved rapidly with treatment, whereas productive cough decreased more slowly and was present in 20% of visits after treatment completion. During treatment, study participants with productive cough more often had concurrent culture positivity compared with those without productive cough (studies 22 and 23: adjusted odds ratio, 1.80; 95% confidence interval [CI], 1.33-2.44). Finally, symptoms during the latter part of treatment and follow-up were associated with culture-confirmed treatment failure and recurrence in studies 22 and 23 (for cough: adjusted hazard ratio, 2.07; 95% CI, 1.23-3.49; for fever: adjusted hazard ratio, 5.05; 95% CI, 2.76-9.19). CONCLUSIONS: There are consistent relationships between symptoms and microbiological indices of tuberculosis, including measures of mycobacterial burden at baseline, culture positivity during treatment, and time to culture-confirmed treatment failure and recurrence.

Rifapentine and isoniazid once a week versus rifampicin and isoniazid twice a week for treatment of drug-susceptible pulmonary tuberculosis in HIV-negative patients: a randomised clinical trial.

BACKGROUND: Rifapentine has a long half-life in serum, which suggests a possible treatment once a week for tuberculosis. We aimed to compare rifapentine and isoniazid once a week with rifampicin and isoniazid twice a week. METHODS: We did a randomised, multicentre, open-label trial in the USA and Canada of HIV-negative people with drug-susceptible pulmonary tuberculosis who had completed 2 months of a 6-month treatment regimen. We randomly allocated patients directly observed treatment with either 600 mg rifapentine plus 900 mg isoniazid once a week or 600 mg rifampicin plus 900 mg isoniazid twice a week. Primary outcome was failure/relapse. Analysis was by intention to treat. FINDINGS: 1004 patients were enrolled (502 per treatment group). 928 successfully completed treatment, and 803 completed the 2-year 4-month study. Crude rates of failure/relapse were 46/502 (9.2%) in those on rifapentine once a week, and 28/502 (5.6%) in those given rifampicin twice a week (relative risk 1.64, 95% CI 1.04-2.58, p=0.04). By proportional hazards regression, five characteristics were independently associated with increased risk of failure/relapse: sputum culture positive at 2 months (hazard ratio 2.8, 95% CI 1.7-4.6); cavitation on chest radiography (3.0, 1.6-5.9); being underweight (3.0, 1.8-4.9); bilateral pulmonary involvement (1.8, 1.0-3.1); and being a non-Hispanic white person (1.8, 1.1-3.0). Adjustment for imbalances in 2-month culture and cavitation diminished the association of treatment group with outcome (1.34; 0.83-2.18; p=0.23). Of participants without cavitation, rates of failure/relapse were 6/210 (2.9%) in the once a week group and 6/241 (2.5%) in the twice a week group (relative risk 1.15; 95% CI 0.38-3.50; p=0.81). Rates of adverse events and death were similar in the two treatment groups. INTERPRETATION: Rifapentine once a week is safe and effective for treatment of pulmonary tuberculosis in HIV-negative people without cavitation on chest radiography. Clinical, radiographic, and microbiological data help to identify patients with tuberculosis who are at increased risk of failure or relapse when treated with either regimen.